Over a hundred thousand public-domain works (mostly pre-1923 books) are available FREE to be read online or downloaded to any reading device. We recommend using the free program Calibre to manage free ebooks on your computer and sync to your reader. Here are just a few sources for free ebooks:

• Project Gutenberg provides plain-text and web-friendly editions, many illustrated, of over 20,000 books (the number grows daily). They can be downloaded in EPUB, Kindle, and other formats.
• PSU's Electronic Classics features great works of literature in PDF format.
• The Black Mask Collection includes early mysteries, science fiction, pulp fiction, satire, and more--a total of about 15,000 titles.
• The Internet Archive has over 300,000 books in their Texts collection, including many facsimiles of art books and others.

Newer items can be found at other libraries.